Echocardiography and heart failure.

Abstract

final pathway for many different types of heart disease. Although it has never been satisfactorily defined, its clinical manifestations are usually recognisable. It reduces exercise tolerance and greatly impairs prognosis, the two aspects at which treatment is aimed. It has recently been suggested that prophylactic administration of ACE inhibitors to all patients a low ejection fraction reduces the frequency of hospital admission and may even prolong life [1]. It would thus seem desirable to investigate the nature of the disturbed physiology present in these patients in more detail. This would increase the understanding of the mode of action of treatment shown to be of clinical benefit. It might even define subgroups within the large number of patients with the clinical diagnosis of heart failure, where conventional treatment was ineffective or even harmful and where some other approach might be more fruitful. In a minority of patients, the heart failure proves to be due to a condition treatable by surgery such as silent valve disease, or malfunction of a valve prosthesis. A second important group are those with complications of acute myocardial infarction such as acquired ventricular septal defect or ventricular aneurysm. Echocardiography has made a major contribution to the management of these patients. Even with M-mode, it was possible to detect an anatomically abnormal valve. A much more comprehensive view was available with cross sectional equipment. Doppler allowed the abnormal pressure drop across the valve to be quantified, so that emergency surgery could often be undertaken without the need for cardiac catheterisation. Silent valvular regurgitation manifested itself by an increase in the amplitude of left ventricular wall motion in a patient with clinical evidence of poor forward flow. A particularly instructive example of this occurred in patients with mitral paraprosthetic regurgitation. This condition is usually clinically silent, presenting only with 'heart failure', yet the correct diagnosis can reliably be made by M-mode alone. Follow-up of patients after valve replacement by echo-Doppler still remains one of the most cost effective applications of the technique. The usual basis for heart failure, however, is ventricular disease, and echo-Doppler has made a major contribution in this field. Ventricular disease may be classified in terms of its anatomy or its physiology. The major anatomical division into hypertrophic, dilated and restrictive disease was one of the earliest achievements of M-mode, and consolidated by 2D. It is covered in the contributions on cardiomyopathy and coronary artery disease. A physiological classification is more complex, and does not always correspond with the anatomical. A restrictive filling pattern may be seen in hypertrophied or dilated ventricles as well as those with classical restrictive cardiomyopathy. The nature of the physiological disturbance should thus be examined in all patients with the clinical syndrome of heart failure, since it often gives useful insights into optimal management.